Fig. 1
Enhanced activation of FDNB peripheral blood LOX1 + PMN-MDSCs with increased anti-inflammatory signals in circulation. (A) Representative flow cytometry results and (B) statistical analysis of the proportion (left) and absolute number (right) of LOX1+ PMN-MDSCs in the whole blood from newborns with normal delivery (NNB, n = 61; female, n = 34; and male, n = 27) and newborns with fetal distress during delivery (FDNB, n = 103; female, n = 54; and male, n = 49). (C) Typical morphology of LOX1+ cells from NNB and FDNB. (D) Statistical analysis of the proliferation rates of CD4+ T cells and CD8+ T cells from NNB and FDNB. Total cells including PMN-MDSCs and total cells excluding PMN-MDSCs were stimulated with anti-CD3/CD28 functional antibodies for 72 h, and the proliferation of T cells was examined by CFSE staining (n = 5). (E) IFN-γ secretion level of TC and TC/LOX1depletion from NNB and FDNB (n = 5). LOX-1+ PMN-MDSCs sorted from NNB and FDNB blood (F-J): (F) mRNA levels of S100A8, S100A9, ARG1, and COX2 (n = 6). (G) Protein levels of S100A9, ARG1, and COX2 were measured by western blotting experiment. (H) Representative flow cytometry results (left) and statistical analysis (right) of S100A9 level (n = 8). (I) Level of arginase activity (n = 8). (J) PGE2 Level (n = 6). (K) NSE levels of plasma in neonates with and without brain injury (uninjured, n = 80; injury, n = 65). (L-Q) Correlation analysis of LOX1+ PMN- MDSCs and plasma NSE level in FDNB (n = 146). (M) Correlation analysis of LOX1+ PMN-MDSCs and TIMP scores in FDNB (n = 135). (N) Correlation analysis of LOX1+ PMN-MDSCs and plasma CRP level in FDNB (n = 151). (O) Correlation analysis of LOX1+ PMN-MDSCs and the length of stay in FDNB (n = 155). (P) Correlation analysis of LOX1+ PMN-MDSCs and plasma PCT level in FDNB (n = 56). (Q) Correlation analysis of LOX1+ PMN-MDSCs and the neutrophil counts in FDNB (n = 59). (R) Expression level of IL-10, TGF-β, IL-1β, and IFN-γ in plasma from NNB and FDNB groups (n = 5). Data are pooled from two independent experiments; *P < 0.05; **P < 0.01; ***P < 0.001; ****P < 0.0001. Bar graphs show the mean ± SEM. Statistical significance was determined using a two-tailed unpaired Student’s t-test (B, D–F, H-K, and R). Spearman’s correlation coefficient and significance (p) are noted for each correlation in (L-Q), and regression lines are shown